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Papers by Daniel Scherzer

One of the most demanding challenges for real-time shadow algorithms is their application to larg... more One of the most demanding challenges for real-time shadow algorithms is their application to large-scale, polygon-rich and dynamic environments. In this paper, we discuss the major problems encountered in applying shadow maps to such an environment and provide practical and robust solutions to the appearing problems. We tackle projection aliasing with the aid of an eye space blur. We compare the major biasing methods to remove incorrect self-shadowing of polygons. Finally we are providing some advancements to the recently published light space perspective shadow mapping method to resolve projection aliasing problems.

Archaeological Prospection. Proceedings of the 9th International Conference on Archaeological Prospection

We present the in 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospectio... more We present the in 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, its objectives and research programme.

ACM Transactions on Applied Perception, 2014

Advanced Rendering Techniques, 2012

ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performanc... more ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performance of walkthrough applications by identifying large parts of the scene as invisible from the camera and rendering only the visible geometry. However, it is of little use for the acceleration of shadow map generation (i.e., rasterizing the scene from the light view [Williams 78]), so that typically a high percentage of the geometry will be visible when rendering shadow maps. For example, in outdoor scenes typical viewpoints are near the ground and therefore have significant occlusion, while light viewpoints are higher up and see most of the geometry. Our algorithm remedies this situation by quickly detecting and culling the geometry that does not contribute to the shadow in the final image.

Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games - I3D '13, 2013

ABSTRACT In offline rendering the algorithm of choice for correctly shadowing transparent objects... more ABSTRACT In offline rendering the algorithm of choice for correctly shadowing transparent objects such as hair or smoke are emphdeep shadow maps. Algorithms trying to achieve the same effect in real-time have hitherto always been limited to approximating the solution by depth-peeling techniques. Since the introduction of Direct3D 11, however, it has become feasible to implement the original algorithm using a single rendering pass from the light without introducing any approximations. In this chapter we discuss how to implement a deep shadow map algorithm for rendering complex hair models that runs in real-time on Direct3D~11 capable hardware, introducing a novel lookup scheme which exploits spatial coherence for efficient filtering of the deep shadow map.

We propose an efficient and light-weight solution for rendering smooth shadow boundaries that do ... more We propose an efficient and light-weight solution for rendering smooth shadow boundaries that do not reveal the tessellation of the shadow-casting geometry. Our algorithm reconstructs the smooth contours of the underlying mesh and then extrudes shadow volumes from the smooth silhouettes to render the shadows. For this purpose we propose an improved silhouette reconstruction using the vertex normals of the underlying smooth mesh. Then our method subdivides the silhouette loops until the contours are sufficiently smooth and project to smooth shadow boundaries. This approach decouples the shadow smoothness from the tessellation of the geometry and can be used to maintain equally high shadow quality for multiple LOD levels. It causes only a minimal change to the fill rate, which is the well-known bottleneck of shadow volumes, and hence has only small overhead.

Temporal coherence (TC), the correlation of contents between adjacent rendered frames, exists acr... more Temporal coherence (TC), the correlation of contents between adjacent rendered frames, exists across a wide range of scenes and motion types in practical real-time rendering. By taking advantage of TC, we can save redundant computation and improve the performance of many rendering tasks significantly with only a marginal decrease in quality. This not only allows us to incorporate more computationally intensive shading effects to existing applications, but also offers exciting opportunities of extending high-end graphics applications to reach lower-spec consumer-level hardware. 7.

Lecture Notes in Computer Science, 2009

A vast amount of soft shadow map algorithms have been presented in recent years. Most use a singl... more A vast amount of soft shadow map algorithms have been presented in recent years. Most use a single sample hard shadow map together with some clever filtering technique to calculate perceptually or even physically plausible soft shadows. On the other hand there is the class of much slower algorithms that calculate physically correct soft shadows by taking and combining many samples of the light. In this paper we present a new soft shadow method that combines the benefits of these approaches. It samples the light source over multiple frames instead of a single frame, creating only a single shadow map each frame. Where temporal coherence is low we use spatial filtering to estimate additional samples to create correct and very fast soft shadows.

Advanced Rendering Techniques, 2012

Computer Graphics Forum, 2011

In this paper, we present new solutions for the interactive modeling of city layouts that combine... more In this paper, we present new solutions for the interactive modeling of city layouts that combine the power of procedural modeling with the flexibility of manual modeling. Procedural modeling enables us to quickly generate large city layouts, while manual modeling allows us to hand-craft every aspect of a city. We introduce transformation and merging operators for both topology preserving and topology changing transformations based on graph cuts. In combination with a layering system, this allows intuitive manipulation of urban layouts using operations such as drag and drop, translation, rotation etc. In contrast to previous work, these operations always generate valid, i.e., intersection-free layouts. Furthermore, we introduce anchored assignments to make sure that modifications are persistent even if the whole urban layout is regenerated.

One of the most demanding challenges for real-time shadow algorithms is their application to larg... more One of the most demanding challenges for real-time shadow algorithms is their application to large-scale, polygon-rich and dynamic environments. In this paper, we discuss the major problems encountered in applying shadow maps to such an environment and provide practical and robust solutions to the appearing problems. We tackle projection aliasing with the aid of an eye space blur. We compare the major biasing methods to remove incorrect self-shadowing of polygons. Finally we are providing some advancements to the recently published light space perspective shadow mapping method to resolve projection aliasing problems.

Archaeological Prospection. Proceedings of the 9th International Conference on Archaeological Prospection

We present the in 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospectio... more We present the in 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, its objectives and research programme.

ACM Transactions on Applied Perception, 2014

Advanced Rendering Techniques, 2012

ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performanc... more ABSTRACT Standard online occlusion culling is able to vastly improve the rasterization performance of walkthrough applications by identifying large parts of the scene as invisible from the camera and rendering only the visible geometry. However, it is of little use for the acceleration of shadow map generation (i.e., rasterizing the scene from the light view [Williams 78]), so that typically a high percentage of the geometry will be visible when rendering shadow maps. For example, in outdoor scenes typical viewpoints are near the ground and therefore have significant occlusion, while light viewpoints are higher up and see most of the geometry. Our algorithm remedies this situation by quickly detecting and culling the geometry that does not contribute to the shadow in the final image.

Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games - I3D '13, 2013

ABSTRACT In offline rendering the algorithm of choice for correctly shadowing transparent objects... more ABSTRACT In offline rendering the algorithm of choice for correctly shadowing transparent objects such as hair or smoke are emphdeep shadow maps. Algorithms trying to achieve the same effect in real-time have hitherto always been limited to approximating the solution by depth-peeling techniques. Since the introduction of Direct3D 11, however, it has become feasible to implement the original algorithm using a single rendering pass from the light without introducing any approximations. In this chapter we discuss how to implement a deep shadow map algorithm for rendering complex hair models that runs in real-time on Direct3D~11 capable hardware, introducing a novel lookup scheme which exploits spatial coherence for efficient filtering of the deep shadow map.

We propose an efficient and light-weight solution for rendering smooth shadow boundaries that do ... more We propose an efficient and light-weight solution for rendering smooth shadow boundaries that do not reveal the tessellation of the shadow-casting geometry. Our algorithm reconstructs the smooth contours of the underlying mesh and then extrudes shadow volumes from the smooth silhouettes to render the shadows. For this purpose we propose an improved silhouette reconstruction using the vertex normals of the underlying smooth mesh. Then our method subdivides the silhouette loops until the contours are sufficiently smooth and project to smooth shadow boundaries. This approach decouples the shadow smoothness from the tessellation of the geometry and can be used to maintain equally high shadow quality for multiple LOD levels. It causes only a minimal change to the fill rate, which is the well-known bottleneck of shadow volumes, and hence has only small overhead.

Temporal coherence (TC), the correlation of contents between adjacent rendered frames, exists acr... more Temporal coherence (TC), the correlation of contents between adjacent rendered frames, exists across a wide range of scenes and motion types in practical real-time rendering. By taking advantage of TC, we can save redundant computation and improve the performance of many rendering tasks significantly with only a marginal decrease in quality. This not only allows us to incorporate more computationally intensive shading effects to existing applications, but also offers exciting opportunities of extending high-end graphics applications to reach lower-spec consumer-level hardware. 7.

Lecture Notes in Computer Science, 2009

A vast amount of soft shadow map algorithms have been presented in recent years. Most use a singl... more A vast amount of soft shadow map algorithms have been presented in recent years. Most use a single sample hard shadow map together with some clever filtering technique to calculate perceptually or even physically plausible soft shadows. On the other hand there is the class of much slower algorithms that calculate physically correct soft shadows by taking and combining many samples of the light. In this paper we present a new soft shadow method that combines the benefits of these approaches. It samples the light source over multiple frames instead of a single frame, creating only a single shadow map each frame. Where temporal coherence is low we use spatial filtering to estimate additional samples to create correct and very fast soft shadows.

Advanced Rendering Techniques, 2012

Computer Graphics Forum, 2011

In this paper, we present new solutions for the interactive modeling of city layouts that combine... more In this paper, we present new solutions for the interactive modeling of city layouts that combine the power of procedural modeling with the flexibility of manual modeling. Procedural modeling enables us to quickly generate large city layouts, while manual modeling allows us to hand-craft every aspect of a city. We introduce transformation and merging operators for both topology preserving and topology changing transformations based on graph cuts. In combination with a layering system, this allows intuitive manipulation of urban layouts using operations such as drag and drop, translation, rotation etc. In contrast to previous work, these operations always generate valid, i.e., intersection-free layouts. Furthermore, we introduce anchored assignments to make sure that modifications are persistent even if the whole urban layout is regenerated.